Hollow body.



N0.83l,638 PATENTED SEP 0. A. WALDO. HOLLOW BODY.

APPLICATION FILED NOV. 4, 1905.

esseg-..-.,,

THE NORRIS PETERS cm, WASHINGTON, n, c.

T.25,190&

UNITED STATES CLARENCE ABIATHAR \VALD 0, OF LA FAYETTE, INDIANA.

HOLLOW BODY.

Specification of Letters Patent.

Patented Sept. 25, 1906.

Application filed November 4, 1905. Serial No. 285,875.

To all whom it may concern.-

Be it known that I, CLARENCE ABIATIIAR IVALDO, a citizen of the United States, residing at La Fayette, in the county of T ippecanoe and State of Indiana, have invented certain new and useful Improvements in Hollow Bodies, of which the following is a specification.

The object of my invention is to produce from thin sheets a cylinder capable of with standing high external fluid-pressures, the construction being such that the cylinder is formed under an initial stress tending to expand it.

The accompanying drawings illustrate my invention.

Figure 1 is a section through the barrel at right angles to the axis, the relative thickness of the material, however, being necessarily magnified. Fig. 2 is a highly-magnified portion of a similar section; Fig. 3, an elevation, and Fig. at an elevation of a form in which the medial portion is a conical frustum.

In the drawings, 10 indicates a seamless cylindrical barrel, which is thin and formed in any desired manneras, for instance, by electrodeposit. A strip of suitable material 1 1 is then cut of a width just sullicient to produce a cylinder which will fit tightly within the cylinder 10. This strip 11 is rolled so that its edges slightly overlap and is then inserted in the cylinder 10, and by means of an expanding mandrel its edges are slipped by each other, so that they closely abut. The cylinder thus formed fits closely within the cylinder 10 and places said cylinder 10 under slight tension and the cylinder 11 under a slight compression. A second sheet 12 is similarly placed within the cylinder 10 11, and other sheets 13 14, &c., are successively placed within the cylinder. As each successive sheet is introduced and expanded, there may be a slight separation of the abutting ends of the preceding sheets, as shown at 15, but the last joint should preferably be a closely-abutting one, as shown at 17. The inner lamina should preferably be of a material having a high resistance to compression.

Each intermediate sheet is preferably surfaced upon both faces with a fusible material .18, so that when the final sheet 14 is placed within the cylinder and. expanded the whole cylinder is subjected while still upon the ex pander to sufficient heat to cause the material 18 to bind all of the several laminae closely together, said material flowing into any of the joints 15 which may have been separated and closely knitting the various laminae together. The heat necessary to flow the binder 18 should not be sufficient to rob the various lamime of their resilience, so that when the parts are held and the binder 18 set there is produced a cylinder which is under an initial expanding stress.

It will be understood, of course, that a body which is a cone or conical frustum may be made in the same manner, as shown in. Fig. 4, to accomplish the same results.

It will also be understood that the tangential stress in the lamina may be made a compressive stress instead of an expansive stress.

I claim as my invention 1. A hollow body comprising an external shell, and a plurality of concentric laminae inserted therein and attached thereto while under external tangential stress, whereby the body is under initial tension.

2. A hollow body comprising an external shell, and one or more concentric sheets insorted si'icccssively therein and expanded in position and connected together to maintain an initial tension.

3. A hollow body comprising an external shell, and a plurality of concentric laminae successively placed therein under an expansive stress, the said. several members being connected by a fusible binder while under said tension.

In witness whereof I have hereunto set my hand and seal, at Indianapolis, Indiana, this 28th day of October, A. D. 1905.

CLARENCE ABIA'IHAR WALDO. 

